mTORC1 is required for TH1 and TH17 differentiation in vitro, but is dispensable for TH2 differentiation. (a) IFN-γ production in wild-type and T-Rheb−/− CD4+ T cells stimulated with anti-CD3 and APCs in TH1 or TH2 skewing conditions, expanded 5 d with IL-2, and restimulated in vitro with anti-CD3 and anti-CD28. (b) IL-17 production in wild-type and T-Rheb−/− CD4+ T cells stimulated with anti-CD3 and APCs in TH1 or TH17 skewing conditions, expanded 5 d, then restimulated with anti-CD3 and APCs in the presence of a protein transport inhibitor. (c) As in a, but for IL-4. (d) CFSE dilution and cytokine production of wild-type and T-Rheb−/− CD4+ T cells labeled and skewed as in a and restimulated with anti-CD3 and anti-CD28 in the presence of a protein transport inhibitor. Data are representative of at least 3 independent experiments.